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N'o. 635,6I3. Patented Oct. 24, I899.

E. L. THOMPSON.

CONVERTIBLE CHAIR.

(Application M Iapt. 18, 1899.)

(No Model.)

woe-sees: [wear/w):

UNITED STATES PATENT OFFICE.

Elli/VIN L. THOMPSON, OF BALDWINSVILLE, MASSACHUSETTS.

CONVERTIBLE CHAIR.

SPEGIFICATION forming part Of Letters Patent N0. 635,613, dated October 24, 1899.

Application filed September 18, 1899. Serial No. 730,804. CNo model.)

To ctZZ whom it may concern.-

Be it known that I, ELWIN L. THOMPSON, of Baldwinsville, county of T Vorcester, State of Massachusetts, have invented an Improvement in Convertible Chairs, of which the following description, in connection with the accompanying drawings, is a specification,

like letters and figures on the drawings representing like parts.

This invention relates to chairs which can be converted at will into a high or low chair or carriage-sueh, for instance, as forms-the subject-matter of United States Patent No. 612,792, dated October 18, 1898.

My present invention has for its object the production of novel locking means for holding the chair in raised position, the construction of said means being such that the greater the weight on the chair-seat the more soon rely will it be locked.

Simpler and stronger framing is also provided, as will be more fully described hereinafter, and particularly pointed out in the following claims.

Figure 1 represents in side elevation and in its high position a chair embodying my invention, the push-handle being broken out to show the locking means in operative position. Fig. 2 is a similar view of the chair in its lowest position. Fig. 3 is an enlarged view in side elevation and partly broken out of the locking means in operative position, and Fig. 4 is a rear elevation of said locking means. 1

The chair-seat A is shown as secured to an X-shaped frame formed by crossed bars 10 20, secured to each other at 15 and to the under side of the seat, making a strong, durable, yet simple and cheap connection between the seat and the legs.- The latter are shown as two pairs CL and b, crossed and pivotally connected to each other at a the legs a being pivotally connected at at to the bars 20 of the frame, the legs I) being connected by links I) to the frame-bars 10, the lower ends of the legs being provided with wheels 20, substantiallyas in my patent referred to.

When the chair islowered, Fig. 2, the body is retained'in proper position by the engagement of the legs a above their fulcrum a with a stop-bar '6, connecting the legs b. A push bar or handle F for the chair when lowered is shown as comprising two arms f, rigidly connected by three cross-bars 7 8 9 and pivotally connected at their lowerends to the legs Z) at f. When the chair is in its high position, Fig. 1, the handle should be drawn up closely to the chair-back out of the way, and when the chair is lowered the handle should be in a convenient position to be grasped by the hands. I will now describe the means by which these results are attained and also the locking means for holding the chair raised.

A strap or bar of metal f is rigidly secured to the cross-bars 8 and 9 of the handle, form- -1ng a longitudinal way, preferably midway,

between the side bars f, said way being in sliding engagement with a guide rigidly secured to the seat A of the chair, as herein shown. I have represented the guide as a plate 9, having rearwardly-proj eotin g lugs or cars g, between which the way passes, a pin 9 extending from one to the other car outside of the way. Upon this pin a locking-dog d is pivotally mounted, the dog being bent or bowed, as clearly shown in Fig. 3, with a projecting lug cl at its upperend extended toward the way f and adapted to enter an aperture] therein, the top of the aperture formin g a locking-shoulderf The other depending end (I of the dog is the heavier and serves as a handpiece by which to release the dog when desired, the end d resting against the way when the dog is in operative position and forming a stop, Figs. 1 and 3, and it will be noticed that the fulcrum g of the dog is above the lug ol and the stop 61 and between them, so that the weight on the chair-seat is transmitted to the dog through the fulcrum, holding the lug in the aperture, the stop 61 preventing the dog from turning in the direction of arrow 50, Fig. 3. The greater the weight the more securely will the seat be locked in position, and the accidental release will be prevented when the chair is occupied-as, for instance, by a child playing with the lockingdog. \Vh'en' the chair is' to be lowered, the end at of the dog is pulled outward, opposite to the arrow 50, until the lug d is withdrawn from engagement with the shoulder f whereupon the chair can be lowered, the dog serving as a handle for the operator to grasp during the descent.

W'hen raising the chair, th e weight of the stop d will automatically act to insert the lug d in the aperture f of the Way when the lug reaches a point opposite thereto. The handle F will be swung out or drawn toward the back of the'chair as the guide approaches or recedes from the pivotal connection of the handle and chair-legs,respectively.

The simplicity and strength of the locking device and its ease of manipulation will be manifest from the drawings and the foregoing description.

Having fully described my invention, what I claim, and desire to secure by Letters Patcut, is

1. In a chair of the class described, the vertically-adjustable body, its legs, a push-handle pivoted at its lower end to the latter and provided with a longitudinal way having a locking-shoulder, a fixed guide therefor on the body, and a locking-dog fulcrumed on the guide, having a lug to engage the shoulder and a stop to bear against the way below the lug, the weight of the occupant acting through the fulcrum upon the dog between the lug and stop to retain the body in raised position".

2. In a chair of the class described, the verticallyadjustable body, its legs, a push-handle pivoted at its lower end to the latter and provided with a longitudinal way having an aperture therein, a guide fixed on the body, and a curved dog fulcrumed on the guide, said dog having a lug at its upper end to enter the aperture, and bearing at its lower end on the way, the Weight on the chair-body acting through the fulcrum between the ends of the dog to maintain the latter in looking position.

3. In a chair of the class described, the vertically-adjustable body, its legs, a push-handle pivoted at its lower end to the latter and provided with a longitudinal way having a locking-shoulder, a fixed guide therefor on the body, and a dog fulcrumed on the guide at the back of the way, the said dog having a lug below its fulcrum to enter the aperture,

the depending end of the dog serving as a handle and also as a stop to bear upon the way belowthe aperture therein, whereby the greater the weight on the body when in raised position the more firmly will the dog be held in looking position.

4. In a chair of the class described, the vertically-adjustable body, its legs, a push-handle pivoted at its lower end to the latter and provided with a longitudinal way having an aperture therein, a guide on the body, having ears to embrace the way, and a locking-dog fulcrumed between said ears and provided with a lug below the fulcrum, to enter the aperture and lock the body in raised position, the depending end of the dog at such time bearing against the way below the aperture to prevent accidental withdrawal of the lug.

5. In a chair of the class described, the vertically-adjustable body, its legs, a push-handle pivoted at its lower end to the latter and provided with a longitudinal way having a locking-shoulder, a fixed guide therefor on the body, and a gravity locking-dog fulcrumed on the guide and adapted to engage the shoulder of the way and lock the chairbody in raised position, the weight on the latter holding the dog in operative position.

6. A convertible chair comprising a vertically-adjustable seat, an Xframe rigidly secured to and depending from it, pivotallyconnected and crossed front and rear legs jointed to the frame, means to lock the seat and legs from relative movement and maintained lockedby the weight on the seat, a handle pivotally connected with the rearlegs, and a connection between the seat and handle and in sliding engagement with the latter.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ELWIN L. THOMPSON. Witnesses:

WALTER P. ABBOTT, THATCHER B. DUNN. 

